Every year hundreds of thousands of consumers buy scam miracle cures for conditions such as weight loss, baldness and impotence.

Many of these products are advertised online or via spam emails. They are often a waste of money, and they can also be dangerous.

That's why you should never start a new medicine, or stop a medicine that has been prescribed for you, without speaking to a qualified health professional first, such as your GP or pharmacist.

The risks of buying medicines online

Some websites offer new medicines and treatments with amazing claims about how well they work.

Other websites appear to sell established prescription medicines, which you may recognise or a doctor may have prescribed for you in the past.

But these medicines may not be real. They may be fake medicines that do not contain the same ingredients. Not only will fake medicine not work like the real medicine, it may also harm you.

If you take prescription-only medicines – which only a doctor or health professional should prescribe for you – without first consulting a doctor, you risk taking medicines that are not safe or not right for you.

If you have a health condition and you stop taking a medicine prescribed for you so you can take a new medicine you bought online, your health condition may get worse.

Avoiding fake (counterfeit) medicines

Legitimate websites selling medicines in the EU have to display a logo showing a white cross on a green striped background. This should link to the MHRA's list of registered online sellers so you can check the site is properly registered.

Some online pharmacies bear the green cross logo of the General Pharmaceutical Council. This means the pharmacy is registered and should be safe to use.

The MHRA warns counterfeit medicines can contain harmful ingredients, such as rat poison and lead-based road paint. They are often produced by people who have no appropriate qualifications in unhygienic surroundings.

It's rare for fake medicines to be produced in the UK. Most of those discovered in the UK come from Asia, in particular from the Far East.

Heart, cancer, anti-cholesterol medicines, anti-psychotics and antidepressants have also been discovered by the MHRA in the UK.

Reporting counterfeit medicines

If you have any concerns or information that could help the MHRA track down people responsible for fake medicines and devices, you can email them at counterfeit@mhra.gsi.gov.uk, ring their 24-hour hotline on 020 3080 6701, or visit the Yellow Card Scheme website.

Common medicines scams

promise a "new miracle cure" or "wonder breakthrough" – in reality, their products are probably not tested or proven to work.

try to convince you with testimonials from previous customers – how do you know these testimonials are genuine? Even if they are genuine, anecdotal evidence like this isn't the same as the scientific evidence genuine medicines are based on.

contain endorsements from a doctor or health professional who quotes scientific evidence – look closer, and you'll see these "doctors" are not attached to any known institution or clinical practice, and the "evidence" hasn't been published in a recognised journal.

Medicines the right way

When it comes to medicines, it's best to speak to a qualified health professional first.

Your GP can help with a range of medicines issues, whether you think you may have a health condition and want to know if medicines can help, or you're already taking medicines and have questions about them.

Your local pharmacist can also help with questions about medicines. If you're already taking medicines, they can offer a medicines use review, where they talk through your medicines with you.